It's not complicated AT ALL!
This is actually one of the most simplest games ever created.

Also a little correction on the rules.
Here is says that when Digivolving to Champion, one needs to send cards offline from the hand.
That is WRONG!
When digivolving to Champion one needs to Offline from the top of their deck.

For example:
Agumon digivolving into Greymon.
Flip Greymon face up on Digivolve Zone, then Offline the top 2 cards from the top of your deck.